第169回 フロンティア材料研究所学術講演会（Prof. Aftab Alam） 12/7開催

開催日時： 　2023年12月7日（木） 13:00 –15:00
開催場所： 　すずかけ台キャンパス R3棟1階 大会議室／Zoomミーティング
オンライン参加の方 ：フォームよりお申し込みください。

「GdAlSi: A potential candidate for altermagnetic topological Weyl semimetal」

講師： Prof. Aftab Alam
（Department of Physics, Indian Institute of Technology Bombay）

概要：
Spintronics has emerged as a viable alternative to conventional electronics in the past few decades. On one hand, discovery of topological phases of matter with protected spin-polarized states have shown promising applications while on the other hand, new magnetic materials have shown in- triguing phases of collinear antiferromagnets with unconventional spin-splitters. In this work, we report the co-existence of these two interesting phases in a single material: GdAlSi. GdAlSi crys- tallizes in a body-centered tetragonal structure with a non-centrosymmetric space group I41md (109). The magnetization data indicates antiferromagnetic (AFM) ordering with an ordering temperature (TN) 32 K. Ab-initio calculations show GdAlSi to be a collinear antiferromagnetic Weyl semimetal (WSM) with an unconventional momentum-dependent spin splitting (also nomenclature as altermagnetism). Fermi arcs, a characteristic feature of WSMs, have been subsequently observed in angle-resolved photoemission spectroscopy (ARPES) measurements performed on GdAlSi single crystals. Electric and magnetic multipole analysis gives a deeper insight into the symmetry mediated momentumdependent spin splitting which has a strictly non-relativistic origin. To the best of our knowledge, such coexistence of unconventional AFM order and non-trivial topology is unprecedented and has never been observed before in any material which makes GdAlSi a wonder material. Finally, we propose a device which can leverage this unique coexistence leading to practical and efficient topotronic application

• フロンティア材料研究所：第169回 フロンティア材料研究所学術講演会（Prof. Aftab Alam）